Field
Embodiments of the present invention generally relate to semiconductor substrate processing systems. More specifically, the invention relates to a cooling mechanism utilized in a plasma processing system with enhanced temperature regulation.
Background
In manufacture of integrated circuits, precise control of various process parameters is required for achieving consistent results within a substrate, as well as the results that are reproducible from substrate to substrate. As the geometry limits of the structures for forming semiconductor devices are pushed against technology limits, tighter tolerances and precise process control are critical to fabrication success. However, with shrinking geometries, precise critical dimension and etch process control has become increasingly difficult.
Many semiconductor devices are processed in the presence of a plasma. The plasma may be easily ignited in processing chambers that utilized capacitively coupled power to energize the gases forming the plasma. However, plasma ignition in other types of processing chambers may not be as easily initiated, often requiring a spike of power to ignite the gases within the chamber. Unfortunately, such power spikes often results in overly high temperature generation to chamber components, which diminish the service life of the chamber components and undesirably generate particles within the processing chamber which undesirably contributes to defect rates.
Furthermore, unstable source of the plasma source or ignition also result in temperature unstable, thereby resulting in temperature gradient formed in the processing environment. Temperature gradient may undesirably create non-uniform distribution of the plasma across the substrate, thereby resulting in etching rate non-uniform, thereby resulting over-etching or under-etching of the resultant structure formed on the substrate. In a deposition process, non-uniform plasma distribution may also result in film profile distortion or incomplete structure formation.
Therefore, there is a need for an apparatus and methods for improving stable temperature regulation during a plasma process within a processing chamber.